Find out and fix tests that have begun failing intermittently on AzDO CI. The tests that are failing are the last two found in the file src/test/common/variables/envVarsProvider.multiroot.test.ts. The test is failing due to the timeout of 20s being exceeded.

One hypothesis is that the tests are failing and being re-run, exacerbating the trouble with async tests accessing the same file. (Rejected due to PR #4479). Another hypothesis is that the timeouts for the test just aren't long enough.

The tests are both set to having a total timeout of 20 seconds. There are 3 places in both tests where an imposed wait of 5 seconds is being processed. This means that the test must complete all other tasks in < 5 seconds. Perhaps the overall test timeout needs to be set to something a bit higher, like 25 seconds for each test.

If it is at all possible, and we could be notified when the configuration has been updated, we could remove the waits added to the tests altogether and reduce the overall time these tests are set to run for.

Hmm, how about we consider re-writing the tests? Wouldn't that be a better approach?
Can get rid of 20s delays, and randomizing file names, etc.

TODO: Refactor the tests.